(_b_) High winds rapidly disperse chemical agent vapors and speed off-gassing from surfaces.
(_c_) Moisture causes chemical agents to react with water to form nontoxic or less toxic chemicals. Heavy rain or rain of long duration can aid decontamination by mechanically removing chemical agents.
(_d_) Even in cold weather, direct sunrays warm surfaces above the air temperature and hasten the off-gassing and decomposition of chemical agents.
_Table J-6. Persistency of Selected Liquid Chemical Agents_
================================================================ | WEATHER CONDITIONS +---------------+----------------+----------------- | | | AGENT | SUNNY, | WET AND WINDY, | CALM, SUNNY, | AROUND 20°C, | AROUND 10°C | LYING SNOW, | LIGHT BREEZE | | AROUND -10°C | | | MUSTARD(HD) | 2-7 DAYS | 1/2-2 DAYS | 2-8 WEEKS TABUN(GA) | 1-4 DAYS | 1/2-6 HOURS | 1 DAY-2 WEEKS SARIN(GB) | 1/4-4 HOURS | 1/4-1 HOUR | 1-2 DAYS SOMAN(GD) | 2-1/2 -5 DAYS | 3-36 HOURS | 1-6 WEEKS NERVE(VX) | 3-21 DAYS | 1-12 DAYS | 1-16 WEEKS =============+===============+================+=================
(6) Active decontamination is attempted only when weathering will not decontaminate the packaging material in sufficient time. Decontamination procedures can be enhanced by using heat to vaporize the chemical agent; by reaction with decontaminants; or by removing with hot soapy water.
(_a_) The simplest (standard) decontamination materials are water and detergents. An effective decontaminant is hot water used with the addition of soap or detergent and scrubbing. Commercial abrasive powdered cleansers are effective decontaminants for many surfaces (metal, glass, Formica), but not wood or soft plastics.
(_b_) Water can be used to flush chemical agents from surfaces. High-pressure application produces a better cleansing action than low pressure. If the surface has absorbed the agent, flushing will remove the surface contamination, but will not affect the agent that is absorbed.
(_c_) Soaking contaminated items in boiling water is an excellent decontamination method for some agents. Water alone will not be sufficient to decontaminate all chemical agents. Soaking in warm or cold water may reduce the contamination slightly; however, the hazard may not be reduced sufficiently even after prolonged soaking. If hot water is not available, or if it might cause damage to the item, other methods of decontamination should be considered, such as decontaminating solutions or a caustic solution followed by thorough rinsing.